Tuberculosis in Sulaimaniyah, Iraqi Kurdistan: A Detailed Analysis of Cases Registered in Treatment Centers.

BACKGROUND
Tuberculosis (TB) remains a major public health problem especially in low and middle-income countries. The current study was undertaken to estimate the incidence of the disease and describe its epidemiological characteristics in Iraqi Kurdistan.


MATERIALS AND METHODS
A retrospective study was carried out on cases registered in the directly observed treatment-short course (DOTS) centers in Sulaimaniyah province. Information was collected from the summary reports of all cases registered in 2010 and detailed information was obtained from 307 cases in the main center.


RESULTS
During 2010, a total of 530 new and relapsed cases were registered in the DOTS centers amounting to an annual incidence of 31 per 100,000. Over 73% of cases were pulmonary TB and 45% of all cases had positive smear. Most common symptoms were cough (58%), sweating (49%) and fever (48). Almost 43% of patients were diagnosed by direct swab examination, 30% by biopsy and 23% through clinical and radiologic examination. In relation to outcome, 89% of patients were treated successfully, 7% died and 3% defaulted. Mortality rate was 8% in pulmonary infection and 4% in extrapulmonary infection. Old age (65 years and over) was significantly associated with higher odds of death compared to people aged 34 years and younger (OR 6.7, 95% CI 1.3-36.1, P=0.03).


CONCLUSION
The incidence of TB is still high in the Iraqi Kurdistan. The DOTS has been successful in treating the majority of cases but there are areas needing improvement especially record-keeping and patient follow-up during and after treatment.


INTRODUCTION
Tuberculosis remains a major public health problem especially in low and middle-income countries. According to the latest report by the World Health Organization (WHO), an estimated 9.6 million new and relapsed cases of TB occurred globally of which around 86% were from Asia and Africa (1). This amounts to a global incidence of around 133 per 100,000 per year. According g to the same report, an estimated 1.5 million people died from the disease, the majority being from Africa and south East Asia and about 400,000 being HIV+ (1). The WHO estimate for the incidence in the Eastern Mediterranean region is 117 per 100,000 per year. However, reports from some countries of the region based on patient records report a lower incidence rate. A retrospective study from Saudi Arabia covering reported cases in 20 years (1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010) estimates an annual incidence rate of 14 to 17 per 100,000 TANAFFOS (2). A recent study from the same country reports a similar incidence of 13.8 per 100,000 in 2011. In Iran, the incidence of TB is estimated at around 12 per 100,000 (3).
Community-based studies have reported a higher prevalence of the disease. The prevalence of smear positive TB was 255 per 100,000 in central India (4), 145 in Vietnam (5) and 34 in China (6).
Like other countries of the region, TB has been a major public health issue in Iraq. The national TB control program was started in 1989 and the DOTS was introduced in 1998 which gradually expanded until in 2008 it covered all 18 provinces (7). According to the WHO, Iraq is among the seven countries of the Eastern Mediterranean region with high prevalence of TB accounting for 3% of cases in the region. In 2014, 8,268 new and relapsed cases of TB were reported in the Iraq resulting in an estimated incidence rate of 43 per 100,000 per year with a case detection rate of 54% (8). Another study conducted in 2011 estimates the total number of cases in Iraq to be 14,500 (95% CI 13,200) with an annual incidence rate of 45 per 100,000 per year (9). The current study was undertaken in Sulaimaniyah province to describe the epidemiology of TB in the province and analyze cases registered at the DOTS centers in relation to demographic characteristics, signs and symptoms and treatment outcomes.

MATERIALS AND METHODS
Sulaimaniyah is one of the three provinces of Kurdistan Region-Iraq with an estimated population of around 1,700,000 in 2010. There is a main TB center in the province center and four centers in the major districts. Information was collected from the summary reports of all cases reported by all centers during 2010. These summary reports are routinely prepared for surveillance purposes.
We used these data to estimate the incidence of TB in the province and provide an overall description of all cases as shown in Tables 1 and 2. In addition to this, detailed information about the cases and their management using DOTS was retrieved from patients' files for 2010-2011 available at the main center in Sulaimani city. Data were transcribed from files and records of patients into a data collection form and later entered into Epidata (10). These were the only files which were available at the center and accessible to the research team. Patients' files included data on demographics, the disease, drugs, outcome and contacts. Descriptive analysis was done in Stata version 9 (11). The research did not involve actual patients but only their medical records. Patients' privacy and confidentiality were respected and the study was approved by the relevant health authorities and the TB center.  Table 1 for other characteristics of these cases (Table 1).   Table 3.

Signs and symptoms
The most common symptoms are shown in Table 4.
Cough was the most common symptom which happened in 58% of patients with a mean duration of 10.5 weeks (SD: 10.7) followed by sweating which happened in 49% of patients with a mean duration of 8 weeks (SD: 9.3). Other common symptoms were fever, fatigue and weight loss (

Outcome
In relation to outcome of treatment, 59% of patients were reported as having recovered, 30% as having completed treatment, 7% died and 3% defaulted. Table 6 shows mortality by different characteristics.

Key findings
The incidence of TB in the province was 31 per 100,000 per year with similar number of cases in males and The mean duration of phase one was 2.1 months and the mean duration of phase 2 was 4.5 months (SD: 2.1). Death was significantly associated with age with an odds ratio of 6.7 in the elderly aged 65 years and over compared to the younger patients aged 0-34 years.

Limitations of the study
This study analyzed cases registered at the DOTS centers; thus, it inherited the limitations of routine data such as missing values, inconsistency, and incompleteness.
Certain information recorded in the files comes from patients telling the history of their disease; therefore, recall bias could not be ruled out. Estimate of incidence is based on cases registered at the centers; thus, it could be an underestimation of true incidence.

Comparison with other studies
The DOTS strategy is built on five key components for According to our study, the incidence of all registered TB cases in 2011was 31 per 100,000 (of which 14 per 100,000 were smear-positive). In the same year, the expected WHO estimate for Iraq was 45 per 100,000 (9). Comparing these two estimates and assuming the same expected incidence for Sulaimaniyah province, the case detection rate would be 69%. Incidence of all forms of TB in the same year was less in Saudis (10 per 100,000) according to Memish et al (14). Our incidence rate was also higher than that of Iran